In the installation of tongue and groove hardwood plank flooring materials, pneumatic staplers are commonly used to drive staples used to adhere the planks to the floor. These staplers are designed to sit flat on top of the hardwood plank and locate against a tongued side of the plank such that they can precisely drive the staple at a 45 degree angle at a point just above the tongue. The driving angle of 45 degrees and driving elevation at the point just above the tongue are fixed and standard for most modern pneumatic hardwood staplers. The standard angle and point of entry for driving staples works well because the hardwood planks themselves normally have standard tongue and groove dimensions.
FIG. 8 shows the shape of a typical modern hardwood staple 50. As used herein, a typical hardwood staple 50 has dimensions defined as follows: dimension 51 is the length of the hardwood staple (sometimes also referred to as a “leg”), dimension 52 is the width of the hardwood staple (sometimes also referred to as a “crown”), and dimension 53 is the thickness of the hardwood staple. Modern hardwood staples are typically wire form products made from round wire. Hence the crown 52 of this kind of staple tends to form a longitudinally rounded surface 54. In comparison to other staples, modern hardwood flooring staples have long, brittle legs that will easily break if they are not supported during the driving process.
FIG. 5 illustrates by way of a cross sectional view the proper stapling of a tongue and groove hardwood plank. A first plank 11 has a hardwood staple 12 driven fully at a 45 degree angle into the vertex 13 of the exterior angle formed by an outer edge 14 and a tongue 15 of first plank 11. Hardwood staple 12 anchors first plank 11 to subfloor 16. Provided hardwood staple 12 is fully driven into the vertex 13 of first plank 11, the tongue 15 of plank 11 fits easily into groove 18 of second plank 17, and the stapling process continues by stapling at same area of the next plank (vertex 19 of second plank 17).
As shown in FIG. 10, the exterior angle formed by tongue outer edge 74 on the tongued side of the plank and a tongue 75 of a typical hardwood plank 71 may not be a 90 degree angle. The angle D of the angled region formed between tongue outer edge 74 and tongue 75 is normally about 89.5 degrees. Similarly, groove outer edge 70 on the opposite groove side of the plank is at an angle E of about 88.5 degrees in relation to a centerline 71 of the plank 11. As shown in FIG. 11, these angles relieve tongue outer edge 74 and groove outer edge 70 from each other when butted together. This ensures tongue outer edge 74 and groove outer edge 70 will only contact near tongue top edge 72, and groove top edge 73. This ensures that there will be minimal interference between the edges which could create a gap at the top of the joint.
In the use of pneumatic hardwood staplers, knots in the hardwood plank or drops in air pressure may cause the nailer to only partially drive the staple, leaving an undesirable exposed staple head. FIG. 6 illustrates the problem. Hardwood staple 10 has been partially driven into the side of the hardwood plank, leaving an exposed staple head 2. Whenever there is an exposed staple head, the tongue of a first plank and the groove of the next plank will not fit together. The floor installation process comes to a halt.
Presently, hardwood installers normally carry snips and conventional nail sets to hammer down partially driven staples. The staple legs have to be separated from the crown, and then the legs can be driven using a conventional nail set. This is a difficult, time consuming process. If a set tool were available to drive the entire exposed staple head the rest of the way into the side of the plank, it would greatly speed the process of installation. The process of driving a partially driven staple or exposed staple head will be referred to herein as a process of “finish hammering” the hardwood staple.
Tools have been developed for hammering nails into the side of tongue and grooved flooring materials, but none for finish hammering modern hardwood staples from pneumatic staplers. For example, U.S. Pat. No. 1,016,383 to Wellman discloses a set tool with a plate which sits flat on the hardwood plank. The plate includes a “V-rib” or 90 degree internal angle surface formed in its base. The V-rib is shaped to conform to the plank at the exterior angle formed by the outer edge of the plank and the tongue of the plank (also referred to as a “rabbet” as this term is used in woodworking). Thus, the V-rib functions to position the plate at a precise location “to permit the effective drive of nails”. A circular “passage” for inserting a round headed nail is formed at a 45 degree angle through the plate to the vertex of the V-rib. Thus, when the point of the nail is inserted into the passage, it is automatically located at the optimal location for driving the nail at a 45 degree angle into the side of the plank.
In addition, the disclosed device of Wellman includes a “punch or driving element” for use in connection with the plate. The punch is a generally cylindrical rod with a reduced outside diameter on one end which can slidably fit within the passage in the plate. This reduced diameter end can slide within the passage all the way to the bottom of the passage, and can thus drive the nail all the way down to the bottom of the passage. Thus, as this disclosure states, “the nail can be entirely driven into the flooring without removing the improved implement” (i.e., the “plate”).
Wellman's floor set may have worked well for the purpose of driving nails, but it is not suitable for the purpose of finish-hammering partially driven modern hardwood staples. The reason is that the passages are merely cylindrical holes designed for the passage of round headed nails. In comparison, modern hardwood staples are fairly thin, U-shaped metal wire form products. Effectively driving such staples requires that the staple be precisely supported all the way into the material by means of a precision staple channel that is shaped to create a precision slide fit with the dimensions of the staple. If a user attempted to drive such a staple with only a hammer, the lack of support means would cause the thin metal legs of the staple to bend over or break. The passage of the Wellman device will not provide the necessary precision support means for supporting the staple.
Other known set tools have been developed for driving staples, but they all have drawbacks. U.S. Pat. No. 1,213,334 to Chapman discloses a single-piece driving rod type staple set with a plurality of “sockets” (i.e., “blind-hole” staple channels) of varying depths formed in its driving head. The reference states that “the sockets are made of gradually decreasing depths so as to accommodate the staple at various stages of its entrance into the wood in which it is being set.” Thus, the user begins by inserting a staple in the deepest channel, and hammers on the opposite end to start the driving process. Once the driving head contacts the wood, the user inserts the staple head into one of the shallower sockets, and the staple can be driven further. The legs of the staple are supported by the various sockets, preventing them from spreading or bending over. This device is not suitable for the purpose of finish hammering hardwood staples because the plurality of sockets requires a wide head. Such a wide head does not easily enter the exterior angle formed by the outer edge of the plank and the tongue of the plank. Furthermore, modern hardwood staples are by comparison much longer and thinner than the staples shown by Chapman. More sockets of even greater depth would be necessary, and the sockets would need to be thinner. Forming enough thin blind sockets into the head would become impractical. Finally, there is no means to maintain the prescribed 45 degree angle during the finish hammering process. What is needed is a tool with a single staple slot with a length at least as long as the hardwood staple, and a means of driving the head of the hardwood staple down the length of the staple channel. The staple channel could be formed at the prescribed 45 degree angle.
Other similar set tools, such as that disclosed in U.S. Pat. No. D493,079 S to Fowler, have more compact, relieved driving heads which include a single staple socket. Such a compact driving head can more easily enter the exterior angle formed by the outer edge of the plank, and the tongue of the plank. However, there is no means of support for the legs of the staple. This type of tool is not helpful in cases where the staple protrudes a significant distance from the hardwood plank. Without support during the driving process, the staple simply bends over.
What is needed is a set tool for finish hammering modern hardwood staples which properly supports the legs of these staples throughout the process of finish hammering while also maintaining the prescribed 45 degree angle and location on the plank where such staples are normally driven.